1. Field of the Invention
The present invention relates to a card operation indicator for magnetic card drive devices which is intended to prevent mishandling of a magnetic card having two recording zones.
2. Description of the Prior Art
Conventional magnetic cards are mostly of the type having a recording zone on one side thereof as shown in FIG. 1 and, consequently, magnetic card drive devices for use with them are also provided with a read/write head on one side only. Only with such a one-sided recording zone, however, the recording capacity of the magnetic card may sometimes be insufficient, and use is made of a magnetic card having two recording zones as shown in FIG. 2. In the case of using such a magnetic card having two recording zones, it is necessary that a read/write operation for the one recording zone be followed by re-insertion of the magnetic card with the front side back for the read/write operation of the other recording zone; otherwise, a special magnetic card drive device must be prepared which is provided with read/write heads on both sides thereof. But such a special magnetic card drive device calls for twice as many read/write heads and head signal processing circuits as those used in the conventional magnetic card drive device, and hence it is more expensive. On the other hand, when the magnetic card having two recording zones is used with the conventional magnetic card drive device having one read/write head, it often happens that the user, once having pulled out the magnetic card after the read/write operation for the one recording zone, forgets to insert it again for the read/write operation of the other recording zone.
Furthermore, in the case where the magnetic card drive device is of the type that the magnetic card is manually handled, a read or write error is apt to occur if the magnetic card is pulled out of the magnetic card drive device immediately after being inserted thereinto. With the magnetic card drive device, it is usually determined that the magnetic card be held still in position for 200 ms or longer after insertion. A short-tempered person, however, when handling the magnetic card, tends to pull it out within about 100 ms.